This invention relates to bellows valves and more particularly to an improved bellows valve with a recessed bellows mounting and employing a stem with long travel with relatively small ports.
There are a wide variety of valves where the sealing means between the stem and the adjacent valve body is a bellows element. The bellows is attached at one end to the valve body and at the other end to the valve stem. The flexible bellows structure permits the necessary stem movement as the bellows is extended and compressed during valve closing and opening.
It has been found desirable in valves of this type to use relatively small valve ports with a substantial valve stem movement to provide for maximum control fluid flow. Such smaller ports permit lower valve closing forces and thus smaller and more easily manipulated actuators. At the same time, the full valve opening resists clogging. A disadvantage of prior valves using long bellows has been the relatively large valve body and stem structure required to mount the elongated bellows.
The improved valve of the present invention has a recessed mounting structure for the upper end of the bellows permitting a substantial reduction in the valve body size and a corresponding shortening of the valve stem. In addition, the improved valve includes a novel and positive acting anti-torque control to prevent bellows twisting and to therefore insure a long bellows life.
Accordingly, an object of the present invention is to provide an improved bellows valve.
Another object of the present invention is to provide a more compact bellows valve having a wide stem opening action.
Another object of the present invention is to provide a bellows valve with an improved anti-torque construction.
Another object of the present invention is to provide a bellows valve with an improved bellows end mounting structure.
Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.